Most quick connect couplings have valve components that remain in the flow path after the coupling is connected and valves opened. The fluid must flow around these restrictions resulting in turbulent flow that increases pressure drop and fluid temperature. Typically, hydraulic systems are over designed to tolerate this energy loss and heat generation. However, some systems, such as liquid electronics cooling systems, strive to minimize pump pressures, heat generation and energy consumption. Therefore, couplings with maximum flow and with an unobstructed flow path are desired.
Another key requirement of a quick connect coupling for an electronics cooling system is minimum spillage of the cooling fluid upon disconnection. This is desired to avoid shorting or other damage to electronic components.
Couplings with rotating ball valves, such as the coupling available from Aeroquip under the Model No. FD83, provide a straight through, unobstructed flow path for maximum flow. The coupling available under the Model No. FD83 is described in U.S. Pat. No. 4,438,779, the entire disclosure of which is incorporated herein by reference. The coupling from Aeroquip under the Model Name Epsilon is another full flow, ball valve, coupling that utilizes concave/convex balls to achieve nearly zero spillage. The coupling available under the Model Name Epsilon is described in U.S. Pat. No. 5,488,972, the entire disclosure of which is also incorporated herein by reference. Although these coupling designs have some of the desired features, they have certain disadvantages such as excessive envelope size due to the ¼ turn lug and groove latching mechanism, dual handles requiring multiple steps to actuate valves, excessive cost, and being only designed in large sizes.
What is needed in the art is a quick connect coupling with an unobstructed flow path to minimize pressure drop and thereby improve system (and/or energy) efficiency and also to minimize fluid spillage upon disconnection and to provide simple, safe operation.